Bacillaenes: Decomposition Trigger Point and Biofilm Enhancement in Bacillus

Bacillaenes are a class of poly-unsaturated enamines produced by Bacillus strains that are notoriously unstable toward light, oxygen, and normal temperature. Herein, in an in-depth study of this highly unstable chemotype, the stability and biological function of bacillaenes were investigated. The structure change of the bacillaene scaffold was tracked by time-course H-1 NMR data analysis coupled with the differential analysis of 2D-NMR spectra method, which was demonstrated to be a domino effect triggered by 4' ,5' -cis (2 and 3) configuration rearranged to trans (2a and 3a). These findings provide the possibility for stabilizing the bacillaene scaffold by chemical modification of its trigger points. In the biofilm assay, compounds 1 and 2 accelerated self-biofilm formation in Bacillus methylotrophicus B-9987 at low concentrations of 1.0 and 0.1 mu g/mL. Interestingly, bacillaenes play dual roles as antibiotic and biofilm enhancers in a dose-dependent manner, both of which serve in the self-protection of Bacillus.

Automated summary

Bacillaenes, a class of poly-unsaturated enamines produced by Bacillus strains, are found to play dual roles as antibiotics and biofilm enhancers. This study reveals the instability of bacillaenes and their potential for stabilizing the scaffold through chemical modification. The findings suggest their importance in self-protection of Bacillus through accelerated biofilm formation in a dose-dependent manner.